Decorative lamp



FIG. 1 is a front perspective view and top perspective view of a decorative lamp, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines in the figures are for the purposes of illustrating portions of the decorative lamp, which form no part of the claimed design. 

CLAIM The ornamental design for a decorative lamp, as shown and described. 